This invention relates to textile marking devices and more particularly to a fabric shademarking device.
As is well known in the garment industry, it is desirable to stamp identifying indicia, ordinarily sequential numbers, along the backside of the fabric web as it is being spread on a spreading table by a fabric spreading apparatus. The purpose of doing this is so that when a stack of cloth parts are cut out from the layers of spread fabric, the pieces of a single layer can be identified and combined together to form a single garment to eliminate any possibility of variations in the color shade of the fabric from layer to layer.
Numerous attempts have been made to produce successful shademarkers. Some such attempts are described in U.S. Pat. Nos. 3,902,413 (Powell et al.), 3,951,397 (Rice) and 3,939,766 (Darwin). In the shademarker described in U.S. Pat. No. 3,939,766, the shademarker consists of a frame which carries printing wheels having a series of indicia printing elements on the peripheries thereof, and which are rotated by movement of the fabric in engagement with the printing wheels. A mechanism is provided for applying ink only to a selected printing element so that all of the printing elements engaged the fabric but only the selected element imprints its image thereon. Means are further provided for rotating the printing wheel in synchronism with the mechanism for applying the ink so that the printing element which is to be inked may be manually selected. The cloth as it passes through the shademarker, which incidentally is mounted on the fabric spreader, passes over an anvil roller on one side of the fabric while a pair of printing wheels press against the fabric on the side opposite from the anvil roller to imprint the shademarking indicia. The motion of the fabric through the shademarker rotates the printing wheels and the inking mechanism as well as an ink roller which inks the inking mechanism.
There are several problems with this type of shademarker. The first problem arises in that a substantial amount of tension is introduced into the fabric because of the fact that the fabric as it passes through the shademarker and onto the spreading table is being used as the motivating force for rotating the printing wheels. This can cause the fabric to be distorted in the spread if it is a loosely woven fabric such as a knit, for example. Another problem is that the tension can produce smearing in the imprinting of the shademarking indicia. Still another problem is that the tension produced in the fabric by means of its contact with the anvil roller and printing wheels may be unevenly distributed across the width of the fabric thereby producing a nip or tuck in the fabric prior to its passing through the printing section of the shademarker. This can result in an interruption in the printed image which renders it unrecognizable.